The present disclosure relates to systems and methods for treating subterranean formations, and more specifically, methods and compositions for controlling pH levels in treatment fluids used in subterranean operations.
Treatment fluids can be used in a variety of subterranean treatment operations. As used herein, the terms “treat,” “treatment,” “treating,” and grammatical equivalents thereof refer to any subterranean operation that uses a fluid in conjunction with achieving a desired function and/or for a desired purpose. Use of these terms does not imply any particular action by the treatment fluid. Illustrative treatment operations can include, for example, fracturing operations, gravel packing operations, acidizing operations, scale dissolution and removal, consolidation operations, and the like. In hydraulic fracturing operations, a viscous treatment fluid (e.g., a “fracturing fluid”) is typically pumped at high pressures down into a wellbore to fracture the formation and force fracturing fluid into created fractures in order to enhance or increase the production of oil and gas hydrocarbons from wells bored into subterranean formations. The fracturing fluid is also commonly used to carry sand and other types of particles, called proppants, to hold the fracture open when the pressure is relieved. The fractures, held open by the proppants, provide additional paths for the oil or gas to reach the wellbore, which increases production from the well.
Maintaining sufficient viscosity in the fracturing fluids used in these operations is important for a number of reasons, including but not limited to control of fluid loss into the formation, effective suspension and transport of proppants, and the like. In some instances, various crosslinkable polymers have been added to the aqueous fracturing fluids to viscosify these fracturing fluids. However, the precipitation of divalent ions from the fluid itself or the surrounding subterranean formation can decrease the viscosity and effectiveness of these treatment fluids. The precipitation of divalent ions occurs primarily in specific pH ranges.
While embodiments of this disclosure have been depicted, such embodiments do not imply a limitation on the disclosure, and no such limitation should be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.